Remove braces from 'when' entry: do not suggest when statement is lambda that has no arrow

#KT-35288 Fixed

idea/src/org/jetbrains/kotlin/idea/intentions/RemoveBracesIntention.kt

@@ -51,6 +51,7 @@ class RemoveBracesIntention : SelfTargetingIntention<KtElement>(KtElement::class
             is KtWhenEntry -> {
                 text = "Remove braces from 'when' entry"
                 return singleStatement !is KtNamedDeclaration
+                        && !(singleStatement is KtLambdaExpression && singleStatement.functionLiteral.arrow == null)
             }
             else -> return false
         }

idea/testData/intentions/removeBraces/whenLambda2.kt

@@ -0,0 +1,10 @@
+// IS_APPLICABLE: false
+fun test(v: Boolean): (String) -> Int {
+    return when (v) {
+        true -> <caret>{ { taskOne(it) } }
+        false -> { x -> taskTwo(x) }
+    }
+}
+
+fun taskOne(s: String) = s.length
+fun taskTwo(s: String) = 42

idea/testData/intentions/removeBraces/whenLambda3.kt

@@ -0,0 +1,9 @@
+fun test(v: Boolean): (String) -> Int {
+    return when (v) {
+        true -> <caret>{ { x -> taskOne(x) } }
+        false -> { x -> taskTwo(x) }
+    }
+}
+
+fun taskOne(s: String) = s.length
+fun taskTwo(s: String) = 42

idea/testData/intentions/removeBraces/whenLambda3.kt.after

@@ -0,0 +1,9 @@
+fun test(v: Boolean): (String) -> Int {
+    return when (v) {
+        true -> { x -> taskOne(x) }
+        false -> { x -> taskTwo(x) }
+    }
+}
+
+fun taskOne(s: String) = s.length
+fun taskTwo(s: String) = 42

idea/tests/org/jetbrains/kotlin/idea/intentions/IntentionTestGenerated.java

@@ -12825,6 +12825,16 @@ public class IntentionTestGenerated extends AbstractIntentionTest {
             runTest("idea/testData/intentions/removeBraces/whenLambda.kt");
         }
 
+        @TestMetadata("whenLambda2.kt")
+        public void testWhenLambda2() throws Exception {
+            runTest("idea/testData/intentions/removeBraces/whenLambda2.kt");
+        }
+
+        @TestMetadata("whenLambda3.kt")
+        public void testWhenLambda3() throws Exception {
+            runTest("idea/testData/intentions/removeBraces/whenLambda3.kt");
+        }
+
         @TestMetadata("whenMultiple.kt")
         public void testWhenMultiple() throws Exception {
             runTest("idea/testData/intentions/removeBraces/whenMultiple.kt");